Roman Schwarz

TL;DR: In this article, a modular, compact, optical lattice clock (OLC) system that achieves a fractional uncertainty of 2.0 is presented, where the clock is operated with bosonic strontium and improves the performance by a factor of 30.

TL;DR: In this article, the authors search for coherent variations in the recorded clock frequency comparisons across the network, and significantly improve the constraints on transient variations of the fine structure constant, for example, constraining the variation to |δα/α| ~10^4 km.

TL;DR: In this paper, the authors search for coherent variations in the recorded clock frequency comparisons across the network, and significantly improve the constraints on transient variations of the fine structure constant, for example, constraining the variation in alpha to ~10^4 km.

TL;DR: In this article, the transition frequency of a strontium-87 lattice clock with low uncertainty was measured by using two local caesium fountain clocks, with low uncertainties.

TL;DR: In this article, the effect of off-resonant scattering of lattice laser radiation by atoms in the two states of {1,S} and {3,P} was investigated and it was found that Raman scattering eventually limits the achievable frequency instability and thus limits the useful interrogation time in optical lattice clocks at presently used lattice depths.